A physical quantity measurement device which detects physical quantity, such as an acceleration sensor, an angular accelerometer, a pressure sensor, a weight sensor, and a magnetic sensor is provided.
A document 1 (JP 2006-71336 A) discloses a physical quantity measurement device which is capable of adjusting an output characteristics.
The physical quantity measurement device disclosed in the document 1 has a sensor circuit including a trimming circuit. The trimming circuit performs an electrically trimming, such as a sensitivity setting, an offset setting, and a temperature offset characteristics, for sensing element. The sensor circuit has only three terminals, namely, a pair of power terminals and one output terminal. One of power terminals is used for grounding.
The above physical quantity measurement device does not require any specific terminal for trimming, because the output terminal is available as an input terminal for inputting trimming data.
Therefore, an external device interoperating with the above physical quantity measurement device needs a plurality of communication devices each of which communicates with each of the physical quantity measurement device, in order to adjust a plurality of physical quantity measurement devices (for example, a sensor module having a plurality of physical quantity detection devices). That is the reason why it is difficult to simplify construction of the external device.
In some cases, the output terminal is directly connected to a load controlled by an output of the physical quantity measurement device. In this case, communicating with the external device through the output terminal is likely to cause malfunction of the load. Moreover, the load is likely to prevent or to limit communication between the physical quantity measurement device and the external device.